ARNICA (Arnica montana)

One of the most trustworthy sources of information for medical doctors in the United States is the Physicians Desk Reference, or PDR for short. There is now a PDR for Herbal Medicines (PDR-HM) and the following statement and excerpt comes from the third edition of this work:

The medicinal use of Arnica goes back many centuries. The essential oil used as a natural remedy in many countries all over the world comes from the flowers leaves and roots of Arnica montana and related species.

Listed or known are antimicrobial, and anti-inflammatory effects. I purposely deleted the word mild from the quote above because elsewhere the words “marked analgesic action” are also used for Arnica.

One of the problems with the literature cited – as with much of the medical literature – is that dose is sometimes ignored or not even mentioned in the studies or the reviews. Unfortunately most American literature is based on homeopathic remedies. These preparations are highly diluted and do probably explain the number of negative studies in the literature. One professor of mine explained that the concentration of “the remedy” in a homeopathic preparation is so low that “you would be lucky if you get even one molecule of it.” Even so, the tenor of this PDR-HM is very positive, and I judge it a good source of information.

Several European countries have herbal medicine pharmacopoeias. One of the most trusted and quoted sources of medicinal herb information is the German Commission E Monographs. (Herbal Medicine, Expanded Commission E Monographs. 2000 by American Botanical Council).

Arnica montana flower

Clinical Trials. Because of the previous statements, we choose to ignore the homeopathy-based studies mentioned in the PDR-HM or found elsewhere as per the references cited below. In one particular negative study cited in the PDR-HM a topical preparation of 0.4% Arnica gel was used (Gulick et al. 1996). This was clearly an inadequate concentration. The actual concentration in our Arthritis Rub is much higher and works every time. We find that when pain is severe it works better if a double application is used for the first 3 to 5 days. The PDR-HM cites un-referenced studies using a gel or a 20% tincture (!) as beneficial to treat muscle aches, edema, venous tone and “feeling of heaviness in the legs.”

There is a study comparing an Ibuprofen gel to topical Arnica for the treatment of osteoarthritis of the hands in 204 patients. Ibuprofen caused a 23.9 % reduction in pain and the Arnica group had a 26.6 % reduction. (Rheumatology International, April 2007; vol. 27, pp.585-91). An Arnica gel was studied to treat osteoarthritis of the knee. Pain was “significantly decreased” with maximum reduction of pain scores after 3 weeks of treatment. (Advances in Therapy. Sept/Oct 2002. Vol. 19 No. 5, pp.209-218).

Indications and Usage of Topical Preparations. Muscle pain especially if applied before and after activities that cause the discomfort. Joints aches and pains, rheumatic joint pain, and associated tendon involvement. The gel or cream should be applied to a wide area around the painful spot. Apply to black and blue areas of skin around blunt trauma. Do not use if skin integrity is broken or cut or scraped raw. It has been successfully used by plastic surgeons to decrease post-op edema and discoloration of the surrounding skin.

Contraindications. Known sensitivity to the daisy family: chamomile, marigold, yarrow. Do not use if pregnant.

Adverse Reactions. Do not use on cut or scraped skin, around eyes, or on mucosal membranes. Although we have not ever seen this phenomenon, the PDR-HM warns that prolonged use can cause sensitization. Discontinue use if a rash occurs. Although very common to see this warning, use along with anticoagulants is not contraindicated. As a precaution, you should tell your doctor to monitor your clotting/bleeding profile if you are going to use Arnica for a prolonged period in the face of anticoagulants.

A private communication with a source in Switzerland reported that this potential problem has been looked at in patients using a 20% topical preparation of Arnica and that not enough of the medicine was detected in blood tests to cause any change in the clotting/bleeding parameters. The warning is more on a theoretical basis without any actual clinical proof.

Overdosage. This is not a concern with the use of topical preparations. Arnica is toxic if ingested. Keep away from children or pets. It is used in very dilute amounts in some wines as a flavoring agent, and in mouthwashes.

Dosage and Mode of Use. Apply the rub to a wide area around the painful muscle, tendon or joint. Wait 5 to 10 minutes and repeat application. Do apply the rub first in the AM or before the activity known to cause pain. Do this again before bedtime or after the activity that causes the pain. After a few days a single application is usually sufficient.